Method of separating gases from mixtures thereof



March 11 1924. 11,486,5211

G. L. HERTZ METHOD OF SEPARATING GASES FROM A MIXTURE THEREOF Filed April 1'7, 1925 Inventcr Gustav Ludwig Hertz.

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To all'whom z'tmay concern: I Y

Be it known that I, Dr. 'Gusrev Luowro many, residing at Eindhoven',in the Prov the Netherlands, have invented certain new and useful Improved Methods of Separating Gases from a Mixture-Thereof, of which the followingis'aspecification. x

This invention relates to an improved method of separating gases from amixture thereof.

it is known that gases can .beseparated.

from a gas mixture by--. assin the 'ases through solidscreens or t roug capil ary.

' The method of separating gases according tothis invention-is based on an entirelyi new characterised in thata gas mixture is made to difluse into a gaseous fluid'fiowing with a.

redetermined velocity. Preferably the ve-' ocity of the gaseous fluid will be regulable and the nature of this fluid will be chosen such that'it can be separated from the gas to he'isolated or'from each of'the gases to I be isolated. Owing to the different diflusion-coeflicients of the diflerent components of the gas mixture the concentration of each of these com onents in the current of gas eous fluid wifi There will he points wherethe concentration of a certain component, which for in stance is most diflusible of all, is relatively high with regard to the concentration of the other less difiusible components.

When removing the gas fraction at such a oint a mixture of theflowing gaseous fluid with said component mafibe obtained in an almost pure condition. y then separating the gaseous fluid from said fraction by a condensation processor a chemical processor in any other suitable manner, the component, separated from the primary gas mixture is obtained dition. 7

At otherpoints in the current of, gaseous fluid, the concentration of a'second gascomp'onent will have increased, which'permits of leading away from this point a gas mixrent velocit 4 or t e case ot difl .flow of gas, ,this'imp'lies as'short a diflusion path as possible. 1 .1

have quite a diflerent course.

in an almostpure conmaybe ma a as fd ifijusion path, "(2) the length of this path and (3) It anmadebythe-latter with the direction of l'llhe currentjvelocity to bechosen of the the gas mixture'and on the desired results.

In order to'obtain the maximum outputv it is- I advisable to design the ap aratus so that it 1 permits of wor 1.

with t e maximum curv gaseous fluid. In the usion-talnng. place against the In carrying out the-invention a vessel may be used, connected to inletand outlettubes for the stream of gaseous fluid, tor the gas mixture to he separated and for the gases which have difl'used apart from each other, while moreover an arrangement can be. provided for separating the gaseous fluid By arranging the inletand' 'outlet-tubes' -in relation to each other in such a way that the gas component to be separated must diti'use against the current, it"is possible to choose the conditions so that only this component is able to do so, the others on the contrary, being led astra by the current to a condenser with which t e apparatus, it desired, is provided, while the component which diflused out is led away from a point of great concentration. and then liberated from the gaseous fluid.

The drawing diagrammatically represents an apparatus for use in carrying out the invention and in which the gases to be separated aremade to diflzuse into water vapour.

Referring to the drawing the apparatus consists essentially of three 3 arts: a water vessel W, ,a difiusion vessel I and a condensation vessel C, which vessels may be in communication as indicated in-the drawing. The three vessels, W, D and C are surrounded by waterjacket'sby means of which their temperature mabe exactly adjusted. The temperature in W should be higher than in and V 'gaseous'fluid depends on thecomposition oiE from the components of the gas mixture.

D and G. The vapour which is developed in W flows through a csipillary a into the upper spherical art of at a current veloclty which isependent on the temperature in W. The temperatures in D and C are regulated so that a portion of the vaour is condensed in D and a ortion in C. n D an inverted funnel-shape tube It is so opened out that betweenthe wall of the funnel and the wall of D a narrow space 9 of length Z remains, through which space the vapour will flow. The ath l is that which. has been termed the illusion path. By making the tube It slidable in a vertical direction the length of the diffusion path may be varied within certain limits, for example, if the tube It is slid upwards the way 1 is shortened, as the enlarged lower part of the tube h remains partly in the upper spherical part of D.

Now a gas mixture of which the total pressure is not greater than the vapour pressure of the water in W', on entering through said tube It in the vessel D will partly diffuse againstthe stream of water vapour, and so arrive in the upper part of D and with the water vapour which is flowing through a tube b, also in G. The composition of this part depends on the diffusion constants of the components of the mixture. Leading therefore through it a mixture of two gases with difl'erent diffusion constants, for instance a mixture of helium and neon, and choosing properly the velocity of the water vapour, only the gas with the greater diffusion-constant (helium) will be able to diffuse against the water vapour, whereas the neon stays almost wholly behind. By these means an almost complete se aration of the gases can be effected. The he ium which has arrived in C, flows with a portion of the water vapour through a very narrow capillary f into an exhausted space V, where the water vapour may be frozen, for instance by means of liquid air, and after thatinto a vessel, where the separated gas is collected in an almost pure condition. The capillary serves to allord the required resistance to the current which,

in consequence of the great difference of pressure in C and V, would otherwise obtain too great avelocity and thus unfavourably influence the diffusion process.' The other component (neon) may be led away by means of a separate outlet-tube k and separated from the water vapour in the same manner as the first component. The inlet-tube h and the outlet-tube k are like wise provided with capillaries. If the component separated" near appears to be insufliciently pure, it may be caused to flow once more through It by the aid of a circulation-device and subjected to the diffusionprocess until said component has obtained the desired purity.

into a gaseous fluid The whole apparatus with exception of the vessel V is placed in an enclosure, in

which the temperature is kept somewhat scribed above. Thus it is not necessary that.

one of the components should difluse against the stream of gaseous fluid forming an angle of 180 therewith but also with much smaller angles very favourable results may be obtained. Neither is it essential that the diffusion path should have the form of a narrow slit. -It should even be possible to'allow the diffusion to take place in the wall of a porous body. Instead of water vapour any suitable gaseous fluid can be used provided that it can be separated from the gases to be collected.

In many cases it will .be desirable or necessary to place several apparatus in a cascade-like series in order to collect the desired gas at the end of the series in a sufficiently pure condition.

It is remarked that the apparatus for separating gases according to the above described method is described in my co-pending application Serial Number 632,7 97.

, What-I claim is:

1. A method of separating the components of a gas-mixture by diffusion consisting in allowing a gas-mixture to diifuse into a gaseous fluid flowing with a predetermined velocity and in removing at least one of the components of the mixture diffused in said streaming gaseous fluid together with part of the latter from places where the concentration of said components to be collected is relatively high with regard to the concentration ofv the other components.

2. A method 'of separating the com-' ponents of a gas-mixture by diflusion consisting in allowing a as-mixture to difiuse into a gaseous fluid owing with a predetermined velocity and which fluid can be separated from at least one of said components and in removing at least one of the components of the mixture diiiused in said streaming gaseous fluid together with part of the latter from places where the concentration of said components to be collected is relatively high with regard .to the con-' centration of the other components.

3. A method of separating the components of a gas-mixture by dlifusion consisting in allowing a as-m1xture to difiuse owing with a predetermined velocity and which fluid can be.

- fusion has taken place.

separated from at least one of said components and in removing at least one of the components of the mixture difiused in said streaming gaseous fluid together with part of the latter from places where the concentration of said components to be collected is relatively high with regard to the concentration of the other components and separating the gaseous fluid from the collected components beyond the place where dif- 4. A -met hod of separating the components of the gas-mixture by diffusion consisting in allowing a gas-mixture to diffuse into a gaseous fluid flowing with a regulable velocity and inremovirfg at least one of the components of'the mixture diffused in.

said streaming gaseous fluid together with part of the latter from places where the concentration of said components to be collected is relatively high with regard to the concentration of the other components.

5. A method of separating the components of the gas-mixture by diifusion consisting in allowin a gas-mlxture to diffuse into a gaseous flui flowing with a regulable velocity and which fluid can be separated from at least one of said components and in removing at least one of the components of the mixture diflused-in said streaming gaseous fluid together with part of the latter from places where the concentration of said components to be collected is relatively high with regard to the concentration of the other components. v

6. A method of separating the components of a gas-mixture by diffusion consisting in allowingi a gas-mixture to diffuse into a gaseous flui flowing with a regulable velocity and which fluid can be separated from at least one of said components and in removing at least one of the components of the mixture diii'used in said streaming gaseous fluid together with part of the latter from places where the concentration of said components to be collected is relatively high with regard to the concentration of the other components and separating the gaseous fluid from the collected components beyond the place where diffusion has taken lace.

7. A method of separatinl the components of a gas-mixture by 'fiusion consisting in allowing a gas-mixture to difiuse the collects .where the diffusion has taken place.

into a streaming gaseous fluid, in choosing the velocity of said fluid as high as possible and in removing at least one of the components of the mixture diffused in said streaming gaseous fluid together with part of the latter from places where the concentration of said components to be collected is relatively hi h with regard to the concentra= tion of t e other components.

8. A method of separatin the components of a gas-mixture by iflusion consisting in allowing a gas-mixture to difiuse into a gaseous fluid flowing with a predetermined velocity and which fluid can be separated from at least one of said components,-

in choosing the velocity of said fluid as high as possible and in removing at least one of the components of the. mixture difiused in said streaming gaseous fluid together with part of the latter from places where the concentration of said components to be col= lected is relatively high with regard to the concentration of the other components.

9. A method of separatin the compo nents of a gas-mixture by iflusion consisting in allowing a gas-mixture to difiuse into a streaming gaseous fluid which fluid can be separate from at least one of said components in choosin the velocity of said fluid as high as possi 1e and in removing at least one of the components of the mixture diffused in said streaming gaseous fluid together with part of the latter from places where the concentration of said components to be collected is relatively high with regard to the concentration of the other components and se aratlng the gaseous fluid from components beyond the place 10. A method of separating the compo nents of a gas-mixture by iflusion consisting in allowing a s-mixture to difluse against a gaseous fluid, flowing with a predetermined velocity and in removing at least one of the components of the mixture diffused in said streaming gaseous fluid to gether with part of the latter from places where the concentration of said components to be collected is relatively high with regard to the concentration of the other components.

In testimony whereof I afia my signature.

Dr. GUSTAV LUDWIG rma'ra. 

